Socket pipe coupling for subsea pipeline systems

ABSTRACT

A socket pipe joint includes a male part and a female part in telescopic overlapping position in the joint. An interlocking sleeve member is provided between the male and female parts. Locking elements including the interlocking sleeve member are provided to releasably lock the male part and female part to one another. A locking sleeve is positioned on the male part and extends from a position inside the female part to a position outside an end opening of the female part. A drive assembly is coupled to the locking sleeve on the outside of the joint and is operable to displace the locking sleeve axially between inner and outer positions. A positioning and interlocking element includes a pawl. By axial displacement of the locking sleeve, the pawl is displaced radially, positioning and interlocking the two pipe parts with simultaneous permanent compression of a seal between the pipe parts.

TECHNICAL FIELD

The present invention relates in general to socket pipe couplings with afemale part and a male part telescopically engaged in a couplingposition. The invention is especially developed for intercoupling pipeline parts in subsea installations, but can also be utilized for otherapplications.

The invention relates especially to socket pipe couplings of the kindwherein is used one or more displaceable sleeves in the joint by radialmovement of usually wedge-shaped clamping members, effecting that thetwo pipe sections are being pressed together to a locked position with asimultaneous compression of interposed seal member or members.

BACKGROUND OF THE INVENTION

There are known a plurality of socket joints of this type. Asillustrative for the prior art one may refer to U.S. Pat. No. 4,652,021,GB 2004341, SE 342495, FR 919287, GB 2223072 and U.S. Pat. No.4,696,493. The two latter US patents are showing solutions wherein areutilized two overlapping displaceable locking rings on the inside of thejoint, which can provide an outwardly directed pressing of wedge-shapedlocking pawls with a simultaneously compressing of interposed sealelements. The coupling itself is carried out with a rotating tool whichis engaged with the internal locking sleeve. A drawback of the beforementioned solutions is that the operation of the joints depends on arotary tool which must be positioned inside one of the pipe parts, andnecessitates that one of the pipe ends is open. A further drawback isthat the packing or seals are positioned on the outside of the joint andtherefore are susceptible to influence from outside environments, forinstance ambient sea water, simultaneously as packings or seals will beexposed to the media inside the pipes.

SUMMARY OF THE INVENTION

The main object of the present invention has been to arrive at a simplerand more rugged construction, which simultaneously results in a highpressure resistant intercoupling and sealing between the respective pipelines and also long durability. A further object of the invention is toprovide a quick connect/disconnect coupling, i.e. a coupling with amechanism which in a simple and quick fashion can be coupled andreleased, preferably by means of a rotating tool which is positioned onthe coupling parts on the outside of the joints.

The socket pipe coupling in accordance with the invention is thus of thekind comprising a male part and a female part in an overlapping positionin the joint, and wherein the coupling includes one or more displaceablesleeves which, subject to pressure against adjacent preferablywedge-shaped locking elements which thereby being pressed outwardly, canprovide interlocking of the pipe parts, simultaneously as the interposedpacking elements are subject to a compression, and the invention ischaracterized in that on the male part in the coupling is positioned alocking sleeve which extends outside of the end opening of the femalepart, and to manoeuvering means fixedly mounted on the male part fordisplacement of the sleeve between an inner position and an outerposition, the sleeve in the inner position pressing against the lockingelements providing compression of an interposed seal member andinterlocking of the pipe parts.

In a preferred embodiment for the invention the locking sleeve on themale part outside the female part is provided with external threads inengagement with an adjacent mounted gear drive which may be operated bymeans of an auxilliary power tool.

The solution in accordance with the invention facilitates use of onesingle, preferably wedge-shaped seal ring made of metal or steel andwhich is positioned in a seat on the inside of the joint between theoutside or the inside of the male part, and an adjacent seat surface atthe bottom of the female socket.

The wedge-shaped locking elements may consist of a number ofcircumferentially distributed, radially movable locking pawls or dogshaving wedge faces in position between the male and the female part inthe joint, respectively, or in the shape of a radially flexible ring, aso called split ring (with a transverse slit)—and which by means of thelocking sleeve may be pressed outwardly from a retracted restingposition to an outer position for engagement between the male part andthe female part, and thereby effect interlocking of the pipe parts inthe joint and compression of an interposed seal member.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Other features and advantages of the invention will appear from thefollowing specification with reference to the enclosed drawings, whichare showing two different applications for the invention, namely a firstapplication wherein the joint is utilized for fastening and coupling ofa valve insert in a valve housing, and a second application whichrelates to the coupling of a well head pipe to a riser pipe for a seabottom installation, wherein

FIG. 1 shows a valve insert for a choke valve of in per se known type,provided with a coupling means in accordance with the invention,

FIG. 2 shows a detail section in a large scale of a part of the valveshown in FIG. 1 which is circumscribed with the circle B in FIG. 1,

FIG. 3 is a sectional lateral view of a pipe joint of the socket type inaccordance with the invention wherein the part to the left of the centerline shows the driving means, partly in section, while the part right ofthe center line shows the coupling in intercoupled position,

FIG. 4 is a lateral view of a similar pipe joint of the socket typewherein the drive means for the coupling mechanism is provided with ahorizontally or laterally directed coupling box with a drive head andwherein the part to the right of the center line shows a section throughthe coupling means,

FIG. 5 is a detail view in section in an enlarged scale of the partshown inside the circle C shown in FIG. 3,

FIG. 6 is a detail view in section showing a special embodiment of thelocking pawls,

FIG. 7 is view similar to FIG. 5 of an embodiment for an inventionwherein the coupling means is utilized for intercoupling two or moreparallel pipe lines or pipe jackets,

FIGS. 8a-e are five detail views which in section illustrates themovement sequence of the parts during the coupling procedure,

FIG. 9 is a perspective view of the split ring member.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a valve insert for a vertically mounted choke valve 2,comprising a lower valve stem 4, an intermediate supporting section 6with valve faces/seats. On the upwardly directed valve stem extension ismounted a box 8 which contains manoeuvering equipment for the valve,including a motor etc. The valve insert is per se known. The valve stemhas an extension 9 on the top with a gripper head 10 serving assupporting and lifting member for the valve insert, and which furthercan be utilized as an emergency operating means.

On the intermediate section 6 of the valve stem is mounted a driveassembly 11 with a bottom plate 12, adapted to be biased against the topface 22 of the valve housing 14, shown in stitched lines. In the shownapplication for the invention the valve housing 14 constitutes thefemale part in the coupling, while the valve stem 4 forms the male part.The number 13 designates elements which are utilized for positioning thevalve insert on the valve housing, and is of minor interest inconnection with the present invention.

The coupling mechanism in accordance with the invention is shown indetail in FIG. 2, which shows a section of the part shown inside thecircle B shown in FIG. 1, and wherein the same reference numbersdesignate the same parts as shown in FIG. 1. Thus, reference number 14designates the socket shaped valve housing with a seat 16 for thepacking or seal ring 18 which as shown preferably consists of a doubleconical ring of metal or steel.

The intermediate part 6 of the valve stem constitutes as mentioned themale part in the joint. On the part 6 is supported an displaceablelocking sleeve 20, the upper part of which is in position outside orabove the top face 22 on the valve housing 14 (the female part) and isprovided with a threaded section 24 which stands in engagement withinward threads 26 on the circumscribing ring gear 28, which isjournalled in the drive assembly, i.e., the gear box 11 on slidebearings at the top and at the bottom. The outside circumference of thering gear 28 is in engagement with a worm gear or pinion 32, providedwith an upwardly pointed fixed shaft top extending out of the gear box11 with a non-circular coupling tap or dowel 34 or the like forpositioning an electric or hydraulic power tool.

The locking sleeve 20 is non-rotatably journalled on the valve stem 4 bymeans of a longitudinal slit 38 made in the side face of the valve stem,whereby is positioned a splint 36, whereby the locking sleeve 20 can bemoved upwards and downwards within defined limits.

The lower part of the locking sleeve 20 is as shown provided with areduced section 40 which is terminated with a transverse biasing face41. The section 40 is tapered in direction downwards, and can serve as awedging face. Adjacent the lower part of the locking sleeve is arrangeda plurality of circumferentially distributed pawls or dogs 42, the upperpart of which has a tapered or wedge-shaped outwardly directed surface44 which is contacting a complementary formed biasing face provided onthe inside of the valve housing 14. The lower part of the locking pawls42 have in the shown embodiment a projection 45 which is positioned in arecess 47 in the valve stem 4 and the bottom face 46 of which is biasedagainst the bottom face 48 in the recess 47.

The coupling joint is in FIG. 2 shown in locked position. In thisposition the locking sleeve 20 has been displaced or driven downwardsalong the stem whereby the tapered faces 40 presses the dogs 42outwardly in wedge-shaped engagement with the surface 44, simultaneouslyas the lower part 45 is guided outwardly along the face 48. The valvestem 4 is thereby simultaneously pressed downwards in the valve housingby means of the locking pawls 42, the top of which will press againstthe transverse surface 41 on the locking ring, while the bottom face 46will press against the surface 48 on the valve stem. Thereby the ringseal 18 will be compressed arresting the valve stem movement,simultaneously as the valve stem is locked with wedging effect by meansof the locking pawls 42. The locking pawls with the adjacent parts aresuch dimensionally adjusted that the movement of the locking pawls willbe stopped by the seal ring 18 before they have reached the bottom,whereby the seal ring 18 will maintain in compression in lockedposition.

When the valve insert shall be released from the valve housing, thelocking sleeve 20 is moved upwards by means of the gear drive 24, 28, 32which is put into rotation by means of a power tool engaged with thedowel 34, ending the locking pawls 42 to be displaced radially inwardsalong the wedged surface 44 simultaneously as they are released from theadjacent part 40 of the sleeve 20, whereby the entire valve insertincluding the valve stem 6, the locking pawls 42, the locking sleeve 20and the gear box 11 can be withdrawn upwards out of the valve housing 14as a unit. The valve can be lowered into the valve insert by gravity.Thereafter the locking sleeve will continue the downward movement.

In FIG. 1 the dowel 34 is arranged with an upwardly directed drive shaft50, which at the top of the valve insert is coupled to a transfer box52, mounted on a transverse stayer 56 positioned on the extension 9 ofthe drive stem. This supplemental device facilitates the access for acoupling tool mounted on a remotely operated vehicle (ROV).

FIGS. 3-7 illustrates a pipe coupling in accordance with the inventionfor assembling an intercoupling of pipes in subsea position, forinstance coupling of a vertical riser pipe on to a production pipe orwell head on a bottom based installation.

FIGS. 3 and 4 are lateral views partly in section, illustrating twoembodiments of the pipe coupling, wherein FIG. 3 shows an embodimentwith vertical coupling drive box 66 a, mounted on an upper male part 60,while the embodiment in FIG. 4 shows a solution with laterally directedcoupling drive box 66 b. In both embodiments the lower pipe section 62is a female part or socket. Disregarding certain detail differences, thecoupling shown in FIGS. 3-7 corresponds to the coupling shown in FIGS. 1and 2 and the same or corresponding parts are to some extent designatedwith the same reference numbers in all figures. In FIGS. 3 and 4, thenumber 62 does designate the socket part in the coupling, while thenumber 60 designates a vertically positioned pipe or male part whichshall be coupled to the socket. The coupling shown in FIG. 3 is shown indetail in FIG. 5, which shows an enlarged section of the part designatedwith the letter C in FIG. 3. The pipe socket is here shown in stitchedlines 62′, while pipe 60 is shown in an inserted, but not tightened andlocked position. This shall be further described later. In FIG. 5 thering gear 64 is mounted in the gear box 66 in the same way as shown inFIG. 2 and is engaged via threads 68 to the locking sleeve 20. The gearbox 11 is mounted on the pipe 60 via a coupling ring 70 which ispressing against the pipe along recesses/ridges 72. The number 74designates elements for positioning a combined guiding and locking pin.

The important constructional difference between the pipe coupling shownin FIG. 2 and FIG. 5, respectively, consists in the design of thelocking pawls 80. In the embodiment shown in FIG. 5 the locking pawlsare, namely, realized as one single closed ring element 80 provided witha transverse slit or slits, one such slit being illustrated at 91 inFIG. 9 (see FIG. 9) such that the ring can flex radially. Similarly asthe pawls 42 of the embodiment of FIG. 2, the split ring 80 includes atransverse oblique surface 83 engageable by a tapered surface 90 of thelocking sleeve 20 and a wedge surface 85 engagable with a generallycomplementary surface 87 on the female part 62. The ring isinterconnected in a gliding finger joint. This so called split ring 80is at the bottom preferably furnished with a supporting ring 82 whichfor instance by means of threads or screws 84 is attached on thelowermost part of the male pipe section. The supporting ring 82 isuppermost provided with throughgoing slits 86 wherein run the heads 88on threaded bolts 89 which leads through slits in the uppermost part ofthe ring 82 and are threaded into the bottom part of the split ring 80as shown. In FIG. 5 the coupling is shown in an intermediate positionwherein the male pipe 60 including the entire coupling has been moveddown into the female part 62 such that the bottom extremity on the malepart is biased against a premounted conical annular seal ring 78 whichpreferably is made in metal or steel. The split ring 80 is positioned inthe spacing between the male part 60 and the female part 62, and hassurface contact with a conically tapered part 90 of the locking sleeve20 simultaneously as the bottom wall plate 92 in the gear box 66 isbiased against the top edge 94 of the female part 62 as shown. When thering gear is activated, the locking sleeve will be driven downwards andpresses the flexible split ring 80 radially outwards, simultaneously asthe screw bolts 89 are being displaced outwardly in the slits 86.

FIG. 6 is a fragmentary view showing an embodiment of locking pawls 80′which constitutes a combination of the pawl design shown in FIG. 2 andFIG. 5 respectively. Herein are utilized individual, circumferentiallydistributed locking pawls 80′, the outside of said pawls and the insideof the adjacent, complementary female part 62′ are provided with astepwise design as also shown in FIG. 5 in replacement of even wedgingfaces as shown in FIG. 2 in order to obtain a positive grip between theadjacent parts.

FIG. 7 is a view similar to FIG. 5, wherein the pipe coupling itself isidentical to the one in FIG. 5, but wherein the pipe coupling isutilized for simultaneous intercoupling two or more parallel pipe linesin a “bundle” (not shown). The coupling comprises a main tubular pipemodule 100 having a center line CL and which is coupled into one singlefemale-part 102 shown in stitched lines. On the right side of the centerline CL are in the male pipe module 100 provided tubular bores 104,while in the female part 102 is provided a complementary pipe-shapedpassage 105 provided with interpositioned annular seal rings 106. Itwill be understood that in a such main tubular pipe module 100 can bearranged two or more parallel pipe lines or bores assembled in onesingle coupling joint 103. On the outside of the gear box 66 are mountedadditional conveying means 108 for one or more cables or the like.

FIGS. 8a-e illustrate the sequence in connection with the couplingoperation. FIG. 8a shows the position where a male part 60 with allfunctional parts has been passed down into an intermediate position in afemale part 62, wherein the bottom plate 92 has not yet arrived intocontact with the top edge 94 on the female part 62. The locking sleeve20 has been driven up to an upper position, enabling that the split ring80 to flex inwardly to an inner position, and remaining in contact withthe lower conical part of the locking sleeve 20. In that position ofsleeve 20, the split ring 80 is spaced from the inside surface of thefemale part 62.

FIG. 8b shows the position wherein the split ring has been presseddownwards in contact with the inside of the female part 62simultaneously as the locking sleeve is pressing the split ring 80outwards. FIG. 8c shows the situation when the split ring 80 has arrivedinto position just above a conically stepped inside of the female part,corresponding to the stepped outside of the split ring as shown.

FIG. 8d shows the position wherein the male part 60 has been presseddown into contact with the bottom of the female part, simultaneously asthe seal ring 78 has arrived into contact with the adjacent insidesurface of the male part. When the locking sleeve 20 now is pressedfurther downwards, the split ring 80 will be pressed radially outwardsand be pressed into engagement with the inside of the female partsubject to a wedge action, simultaneously as the ring seal 78 issubjected to high compression. The dimensions and the position of thesplit ring 80 with cooperating engagement faces on the outside of thesplit ring and the inside of the female part 62 and the packing seal 78,respectively, are such calibrated that the seal ring will determine thefinal position of the male part 60. In this fashion the seal 78 will besubject to a locked compression in the coupling.

A substantial advantage with the pipe coupling in accordance with theinvention is that the entire coupling procedure can be carried out onthe outside of a ready assembled coupling and that the coupling can becarried out by means of one single auxiliary power tool. In addition toa safe and quick coupling, release and disengagement of the couplingparts, the present invention makes it possible to intercouple two orseveral parallel pipe lines by means of a module assembly, wherein twoor several pipes or the like with complementary pipe coupling arepresent.

Intercoupling two or several parallel pipe lines is very important inconnection with subsea constructions, wherein the female parts arevertically mounted on a bottom frame and the male parts shall be coupledthereto. The male parts including the coupling implements can then bemounted on a modular frame, which thereafter are lowered down intoposition on a complementary module with female parts, whereafter thefinalizing intercoupling takes place by means of a procedure which isillustrated in FIG. 7.

On the male part may in operational vicinity to the gear housing bearranged a skirt or funnel-shaped device, dimensioned to circumscribethe female part in the coupling. A such device may facilitatepositioning and lowering of the male part into the below positionedfemale part, for instance an outwardly pointing well head or the like.

What is claimed is:
 1. A socket pipe joint comprising: a male part and afemale part telescopically and axially interconnected in the joint;locking elements for releasably locking said male part and said femalepart relative to one another including at least one elongated lockingsleeve between the male part and the female part, said elongated lockingsleeve being located on the male part and, in said joint, extending froma position within the female part to a position outside an end openingof said female part, said locking sleeve having a generally annulartapered surface; and a drive assembly positioned outside the jointmounted on the male part to displace said locking sleeve along said malepart between locked and unlocked positions, said locking elementsincluding at least one pawl having a transverse surface engageable bysaid tapered surface of said locking sleeve and a wedge surfaceengageable with a generally complementary surface on said female part,the transverse and wedge surfaces of said one pawl being cooperable withthe tapered surface of said locking sleeve and said complementarysurface of said female part, respectively, to position and lock the malepart and female part to one another in response to displacement of saidlocking sleeve in one axial direction.
 2. A socket pipe joint accordingto claim 1 wherein said locking sleeve includes drive surfacesengageable by said drive assembly mounted on the male part.
 3. A socketpipe joint according to claim 1 wherein said drive assembly comprises agear unit having a head for engagement by a rotary power tool.
 4. Asocket pipe joint according to claim 1 wherein said pawl comprises aplurality of circumferentially spaced, radially displaceable pawlmembers disposed between positions on the inside of said male part andcomplementary positions on the inside of the female part.
 5. A socketpipe joint in accordance with claim 4 wherein an intersection of saidlocking sleeve is positioned on the inside of said pawls and responsiveto displacement of said locking sleeve to displace the pawls outwardlyinto a biasing position on the inside of said female part whereby saidmale part and said female part interlock relative to one another.
 6. Asocket pipe joint according to claim 5 including a seal between an innerend part of said male part and an adjacent inside face of said femalepart for sealing said male part and said female part to one another. 7.A socket pipe joint according to claim 5 wherein said seal is subjectedto compression by radially outwardly directed movement of said pawlswhen said pawls are in a biasing position between said male part andsaid female part, respectively, whereby said male part and said femalepart are interlocked to one another in the coupling affordingcompression of said seal.
 8. A socket pipe joint according to claim 1wherein said pawl comprises a continuous integral ring member of metal,said ring member being transversely split affording radial flexibilitythereto.
 9. A socket pipe joint according to claim 1 wherein each ofsaid male part and said female part circumscribes two or more paralleltubular pipe lines in respective communication with one another, each ofthe communicating pipe lines being connected by a coupling joint mountedbetween the male part and female part comprised of a seal ring mountedin adjoining ends of the communicating pipe lines of the male and femaleparts, respectively, each said pipe line being intercoupled withsimultaneous compression of each of said seal rings upon intercouplingthe male part and the female part.
 10. A socket pipe joint comprising: amale part and a female part telescopically interconnected in the joint;locking elements for releasably locking said male part and said femalepart relative to one another including at least one elongated lockingsleeve between the male part and the female part, said elongated lockingsleeve being located on the male part and, in said joint, extending froma position within the female part to a position outside an end openingof said female part; a drive assembly positioned outside the jointmounted on the male part to displace said locking sleeve along said malepart between locked and unlocked positions, said locking elementsincluding at least one pawl cooperable between said male part, saidfemale part and said locking sleeve to position and lock the male partand female part to one another; said drive assembly including a ringgear circumscribing said male part and said locking sleeve, said ringgear provided with internal threads in engagement with threads on thelocking sleeve, said ring gear lying in engagement with the gear drive.11. A socket pipe joint comprising: a male part and a female parttelescopically interconnected in the joint; locking elements forreleasably locking said male part and said female part relative to oneanother including at least one elongated locking sleeve between the malepart and the female part, said elongated locking sleeve being located onthe male part and, in said joint, extending from a position within thefemale part to a position outside an end opening of said female part; adrive assembly positioned outside the joint mounted on the male part todisplace said locking sleeve along said male part between locked andunlocked positions, said locking elements including at least one pawlcooperable between said male part, said female part and said lockingsleeve to position and lock the male part and female part to oneanother; said locking sleeve being mounted for non-rotationaldisplacement along said male part in an axial direction by a splint andgroove cooperable between said male part and said locking sleeve.
 12. Asocket pipe joint comprising: a male part and a female parttelescopically interconnected in the joint; locking elements forreleasably locking said male part and said female part relative to oneanother including at least one elongated locking sleeve between the malepart and the female part, said elongated locking sleeve being located onthe male part and, in said joint, extending from a position within thefemale part to a position outside an end opening of said female part; adrive assembly positioned outside the joint mounted on the male part todisplace said locking sleeve along said male part between locked andunlocked positions, said locking elements including at least one pawlcooperable between said male part, said female part and said lockingsleeve to position and lock the male part and female part to oneanother; said pawl comprising a continuous integral ring member ofmetal, said ring member being transversely split affording radialflexibility thereto; said split ring member being radially movablymounted on a support ring mounted at an inner end of said male part. 13.A socket pipe joint according to claim 12 wherein said support ring hastransverse slits therein, said split ring member being mounted on thesupport ring by bolts having heads positioned in said transverse slits.14. A socket pipe joint comprising: a male part and a female parttelescopically interconnected in the joint; locking elements forreleasably locking said male part and said female part relative to oneanother including at least one elongated locking sleeve between the malepart and the female part, said elongated locking sleeve being located onthe male part and, in said joint, extending from a position within thefemale part to a position outside an end opening of said female part; adrive assembly positioned outside the joint mounted on the male part todisplace said locking sleeve along said male part between locked andunlocked positions, said locking elements including at least one pawlcooperable between said male part, said female part and said lockingsleeve to position and lock the male part and female part to oneanother; said pawl comprising a continuous integral ring member ofmetal, said ring member being transversely split affording radialflexibility thereto; said split ring member including ring-shaped stepswith oblique surfaces along outer surfaces thereof and matingcomplementary steps on the inside of the adjacent female part, enablinginward displacement of said locking sleeve to clamp said split ringmember against said female part by a wedging action simultaneously assaid seal is placed in compression by axial movement of said male partagainst said seal.